Caroline Wozniacki follows through on a serve during her quarterfinal match at the 2014 U.S. Open.USA TODAY Sports

Peng Shuai and Caroline Wozniacki will meet in a semifinal at the 2014 U.S. Open that features a late bloomer against a former No. 1 player.

No matter which player prevails, this weekend, one of them will be playing for their first Grand Slam title.

Peng, 28, will be playing in her first Slam semifinal. It will be the fourth semifinal appearance for 24-year-old Wozniacki.

Peng, ranked No. 39, reached a career-high No. 14 ranking in 2011 before a slow skid down. After defeating Belinda Bencic in the quarterfinals, an emotional Peng told the crowd at Arthur Ashe that she once considered giving up.

Wozniacki is experiencing her own revival. After swiftly moving up the rankings as a teen, Wozniacki fell out of the Top 10 earlier this year. She also went through a public breakup with her former fiancee Rory McIlroy.

Affirmation and celebration awaits the winner.

Who Has the Historic Edge?

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Caroline Wozniacki shakes hands with Peng Shuai after winning a match in New Haven in 2013.Elsa/Getty Images

They last played last summer in New Haven. Peng took the first set 6-2, but retired in the second set with Wozniacki up 3-1. Peng's only victory came in Toronto in 2007. Wozniacki was still a teenager.

Wozniacki has also enjoyed more success at Flushing Meadows. She reached the finals in 2009 and lost to Kim Clijsters. Wozniacki advanced to the semifinals in 2010 and 2011. Prior to reaching the semifinals, Peng had never advanced beyond the fourth round.

How Peng Has Looked so Far at the US Open

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Shuai Peng serves during a match at the 2014 U.S. Open.Elsa/Getty Images

Appearing in her 37th Grand Slam, Peng finally made it to the semis. She's done it with relative ease. She has yet to drop a set.

She upset No. 4 seed Agnieszka Radwanska in the second round. She defeated Lucie Safarova in the third round. Safarova, who reached the semifinals at Wimbledon, is the hardest-hitting player Peng has faced.

She blew past teen-sensation Bencic, 6-2, 6-1 in the quarterfinals. Bencic, accustomed to the power game, appeared caught off guard by Peng's craftiness. Bencic told reporters that "I think she has a dangerous game with both hands and the ball is really coming different from her racquet. I had a little bit troubles with this today. Also angles are great."

How Wozniacki Has Looked so Far at the US Open

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Caroline Wozniacki hits a forehand during her quarterfinal match against Sara Errani at the 2014 U.S. Open.Streeter Lecka/Getty Images

Wozniacki trounced Sara Errani, 6-0, 6-1 in the quarterfinals.

The match was built as a defensive battle. However, Wozniacki played aggressively, racing to take the first set in 29 minutes. Errani had no answer for Wozniacki who hit 26 winners and just 10 unforced errors.

Wozniacki's toughest test came in the fourth round against Maria Sharapova. After dropping the second set 2-6, Wozniacki shocked the No. 5 seed by taking the final set 6-2. Wozniacki's average first-serve speed of 100 was higher than Sharapova's.

Biggest X-Factors in the Semifinal

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Shuai Peng serves during her quarterfinal match at the 2014 U.S. Open.USA TODAY Sports

Battle readiness, unforced errors and first-serve percentage will be the biggest X-factors for this match.

When two players with superb defensive skills clash, the edge goes to the most efficient. Who will make the fewest unforced errors?

Because both women are masterful retrievers, it will be important to land first serves.

One major factor in Wozniacki's favor is the draw she fought through. Although Peng beat accomplished veterans like Radwanska, Vinci and Safarova, she hasn't had to survive the big hitters that Wozniacki played through.

Peng Will Win If...

Peng pumps her fist during her quarterfinal match at the 2014 U.S. Open.USA TODAY Sports

Peng plays the percentages well. Against Wozniacki, Peng has to do better than well. Wozniacki is a counter-puncher who packs a punch.

Peng, who has no lethal weapons in her arsenal, has to mix it up and take chances at the net. She needs to throw in some top-spin lobs, a few drop shots and slices. She must do whatever she can to disrupt Wozniacki's rhythm.

Wozniacki Will Win If...

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Wozniacki during her quarterfinal match at the 2014 U.S. Open.Matthew Stockman/Getty Images

Wozniacki has the better all-around game. She is faster and fitter. However, Peng, part of one of the best doubles teams, can get sneaky at the net.

Wozniacki must dictate the play and deny Peng chances to display her net-play magic. Wozniacki must also remain relentless in applying pressure on Peng's serve. Peng hits a first serve as hard as Wozniacki's. However, the second serve looks more like Errani's. Wozniacki must jump all over it.

Prediction

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Caroline Wozniacki celebrates a win over Maria Sharapova at the 2014 U.S. Open.Chris Trotman/Getty Images

Odds are usually in favor of the more experienced player. Although Peng has the longer career, Wozniacki has more experience in big matches on tennis' biggest stage.

Both women have healthy winners/unforced errors ratios. However, Wozniacki can do more damage with her weapons.

Playing like a woman who's figured it out, Wozniacki will impose her game on Peng. She will take it in straight sets, 6-3, 6-4.